REPORT ON THK RAD1OLARIA. 



five to six on tlie radius. Between every three meshes arises a short radial thorn, as long as the 

 thickness of the shell-wall. Six radial spines sceptre-shaped, six-sided, somewhat constricted 

 towards their middle part, strong, as long as the radius of the outer shell, as broad as one of its 

 meshes. Radial proportion of the three spheres =1:2:6. Pores of the two inner shells regular 

 hexagonal, with thin bars, six to eight on the half meridian (fig. la). 



Dimensions, Diameter of the outer shell 0'13, of the middle 0'04, of the inner - 02 ; pores of 

 the outer shell O01, of the middle 0008, of the inner 0-004 ; length of the six spines 0'06, basal 

 breadth 0'015. 



Habitat. Equatorial Atlantic, Station 347, surface. 



11. Hexacontium prionacanthum, n. sp. (PI. 24, figs. 7, 7). 



Cortical shell thick walled, thorny ; its pores regular circular, with elevated hexagonal frames 

 six to nine on the radius, twice as broad as the crest-shaped bars. At each nodal-point of the 

 hexagon arises one short conical papilla or thorn. Radial proportion of the three spheres = 

 1 : 3 : 10. Pores of both medullary shells much smaller, regular circular. Six main spines three- 

 sided prismatic, longer than the radius of the outer shell, as broad as one of its meshes ; their three 

 edges serrated, with ten to twelve teeth. 



Dimensions. Diameter of the outer shell 0'15, middle 0'045, inner O'Olo ; cortical pores O'Ol, 

 bars O'OOo ; length of the spines 01, breadth 0'012. 



ffabitat. West Tropical Pacific, Station 225, depth 4475 fathoms. 



12. Hexacontium clavigerum, n. sp. (PI. 23, fig. 5). 



Cortical shell very thick walled, thorny ; its pores regular circular, hexagonally framed, three 

 times as broad as the bars, nine to twelve on the radius ; between them short conical papilhe or thorns 

 arising at the nodal-points. Radial proportion of the three spheres = 1:2:5. Outer medullary shell 

 with regular circular, much smaller pores ; connected with the cortical shell by numerous (twenty to 

 thirty) thin radial beams. Six main spines very stout, club-shaped, scarcely as long as the radius 

 of the outer shell, three times as broad as one of its pores, three-sided, with three to four teeth on 

 each edge. 



Dimensions. Diameter of the outer shell 0'2, of the middle 0'08, of the inner 0-04 ; cortical 

 pores 0-012, bars 0'004 ; length of the six spines 0'08, breadth 0'03. 



H,,lHl,il. South Atlantic, Station 332, depth 2200 fathoms. 



13. Hexacontium fioridum, u. sp. (PI. 24, fig. 4). 



Cortical shell papillose, thick walled. Pores regular, six-lobed, four times as broad as the bars, 

 five to seven on the radius ; each pore with six (sometimes also five or seven) concave indentations or 

 lobules ; between the pores at the nodal-points arise short conical papilla? or thorns. Radial pro- 

 portion of the three spheres =1:2:3. Radial main spines pommel-shaped, three-sided prismatic, 

 longer than the radius of the outer shell, two to three times as broad as one pore. 



